Process of making a lamp shade



United States Patent C) ice to-DonLStefaniandone-third to Roy I. Stefani, both of Oakland, Calif.

Application February 23, 1954, Serial No. 412,019

2' Claims. (Cllv 154-110) The. present invention relates to the process of making a lamp shade, and' in more particular to a lamp shade made from a sheet of translucent solidified foam polystyrene resin which has had'its light diffusing power increased by reducing: thethickness of the sheet by compression thereof while in itssolidified state.

There have been many' and various materials used as coverings and light diffusers in the constructioir oflamp shades. Some of these materials have been: light in weight, some have been heavy, some have requiredlittle framing for their support on av lamp andaothcrs such as cloth have required much. However, applicant'knows of no material other than that formingthe subject of the present invention, which lends itselfto the formation of a lamp shade withas little framing; or support, as the present material and, yet, which is light in weight, dimensionally stable whenformed, and has the desirable light transmitting and diffusing powerdesired.

Hence, objects of the present invention are to find, process, devise, and form a material so that it will have high light diffusing and transmitting characteristics, will be light in weight, will be dimensionally stable when formed, and self supporting, and to fabricate said material into a lamp shade of attractive appearance.

The invention possesses other objects and features of advantage, some of which, with the foregoing will be 'set forth in the following description of the preferred form of the invention which is illustrated in the drawing accompanying and forming part of the specification. It is to be understood, however, that variations in the showing made by the said drawing and description may be adopted within the scope of the invention as set forth in the claims.

These objects are achieved and the defects of the prior art remedied by the use in a lamp shade of a sheet of solidified-foam polystyrene resin which initially is very translucent and thick but has been processed by passing it through rollers to obtain a thickness reduction of about half its original thickness, and of coating both sides of the sheet with a pigmented shellac to give the shade a desired color and to bind to the sheet any particles of the material thereof which may have become loosened in the processing of the sheet.

A lamp shade formed in accordance with the above outline and the present invention, and which achieves the objects of the invention is hereinafter described in detail and shown in the accompanying drawings, in which:

Figure 1 is a perspective view of one form of lamp shade embodying the present invention.

Figure 2 is a sectional detail at one of the three connecting points between the shade and its supporting spider, and is of the form shown in Figure 1, taken on the line 22.

Figure 3 is a sectional detail of one of the connecting points between the shade and spider, and shows another form of construction which may be used.

Figure 4 is a plan view showing a still further modification of a spider for support of the shade.

In thedrawings, Figure l is a perspective view of a shade and its supporting spider, which embodies a preferred form of the invention. In the description of the present device the word shade is used to designate both the entire assembly as shown in Figure l and the covering 11 as this covering constitutes the major part of the completed article in contrast to many of the prior devices in which the covering is a small part and the frame is the major part. This covering is self supporting, that is, it will stand alone and keep its shape without other means. The spider His only ameans forattaching the shade to the harp of a lamp. In use, the spider ring 13 would receive the bolt ofthe harp and be secured thereon by a nut. Extending. outwardly. from the spider ring 13 are three spokes 14,-. the outwardend of each spoke terminating. adjacent the shade 11. Each spoke is secured to the shade by oneof the means shown in Figures 2, 3, and 4. Edges of the piece from-whichthe shade is formed are bevelled, cemented, and butted to form a scarfed joint 15.

In Figure 2 the spoke-shade fastener consists of a hollow rivet 21 that receives in its hollow stem the end of the spoke 14, and'a washer 22 which is secured on the stem of the rivet. The head of the rivet is outside of the shade 11 and the Washer 22 is on the inside. The shade. is held.- between the rivet head and the washer. Ihd'entations- 23 in the stem' of the-rivets serve to bind the rivet to the. spoke. Out-struck. portions 24 of the washer serve to'bind the washer on the stemof the rivet and'prevent itsremoval therefrom when once set thereon.

In Figure 3 there has been added a-- hoop; 31 that extends around the inside of the shade and thereagainst. The ends of the spokes 14 re'st against and below the hoop 31. A small piece of sheet metal forms a clip 32 which has at each side ears 33 so formed that when the clip is placed above and adjacent the end of a spoke the ears may be bent downward and around the spoke to secure the clip thereto. -The outer end 34 of the clip is bent up and offset with respect to the spoke embracing part, rests on the hoop, and extends into the material of the shade 11. Thus the shade, spokes, and hoop are secured together. In this construction and in the construc tion of Figure 4, there is no showing outside of the shade of the manner in which the spider is secured to the shade.

In Figure 4 there is shown a plan view of a modified form of shade-spoke fastener, which fastener is extremely simple in design and function. In this modification the outer end of each spoke 14 is extended by a lengthened portion of the spoke being bent or attached thereto at right angles to the spoke to form a shoulder 41 which may bear against the inside of the shade 11, and by a further extension outwardly into the material of the shade to form an anchor 42. In this modification of the spider 12, it is best to integrate the spider and shade during the forming process of the shade, as will now be described.

The shades 11 are formed from sheets of solidifiedfoam polystyrene resin. A trade name for such a material is Styrofoam manufactured by The Dow Chemical Company of Midland, Michigan. These sheets as received for processing are white in color, have rough textured faces as they have been cut from larger blocks or sheets of the material, and many of the small cells have been cut open in the shaping of the sheet. The interior of the sheet is a cellular mass of discontinuous air pockets-from /s to inch average diameter-each totally enclosed in a continuous polystyrene membrane so that the sheet is impervious to moisture and will not absorb material amounts of moisture when immersed in water. The material weighs about 1.5 to 2 pounds per cubic foot. Although the material will not take a very large compressive load it is quite rigid. These sheets at the start of the process are about /4 inch thick. A sheet Patented Nov. 12,- 1957 is passed between rolls which are set to crush the sheet to a thickness of about inch, a reduction of about one-half. Preferably, three compression rolls are used and arranged to give the desired roll or curvature to the finished product while at the same time compressing the same. One side of the sheet, the side which is to form the inside face of the shade, is then sprayed with a pigmented shellac to give the desired color to the sheet and to bind thereto any particles of the sheet which may have been loosened therefrom. This painting, also, gives a smoother surface which keeps the shade more dust free. The sheet may then be cut to give a piece of the exact size required for the finished product, and placed on a jig around which it is formed to the desired final shape. Usually the jig holds the spider l2, and in the case of using the shade-spoke fastener of Figure 4, the anchors 42. are forced into the shade as it is shaped onto the jig. The scarfed ends of the piece are treated with a suitable cement and butted to form the joint 15. When the joint has set,.the shade may be removed from the jig and the outside given a spray coat of pigmented shellac to match the inside. When dry, the shade is complete.

If the fastener of Figure 2 is to be used, the shade may be drilled or punched at the proper places to receive the fasteners, and the fasteners placed and secured to the spider spoke ends while the shade is in the jig. If the fastener of Figure 3 is used, it may, also, be placed and secured to the spokes and hoop as shown in this figure while the shade is in the jig.

The shade when formed as above described, is rigid, light in weight, and pleasing in appearance. The passing of the sheet between rolls to reduce its thickness, increases the light diffusing quality of the material. This step is an important aspect of the present invention.

Having thus described my invention, I claim:

1. The process of constructing a lamp shade, comprising: cutting a sheet of solidified-foam polystyrene resin into generally rectangular form with parallel longitudinally extending edges, passing said sheet between rollers to obtain a reduction in the thickness thereof, applying a coating to one of the faces of such reduced sheet, then shaping such piece into generally cylindrical form with a suitable support frame secured thereto and with the side edges in abutting relationship, and finally applying a coating to the other face of such piece.

2. The process of constructing a lamp shade, comprising; passing a sheet of solidified-foam polystyrene resin between rollers to obtain a reduction of about one-half in the thickness thereof, applying a coating to one of the faces of such reduced sheet, after reduction of such sheet cutting the sheet to obtain a desired sized piece of trapezoidal form, then manipulating such piece to form with a frame a lamp shade of generally frusto-conical form with such coated face interiorly of such shade and with the sheet ends in abutting relation, adhesively securing together said abutting ends, and finally applying a coating to the other face of such piece.

References Cited in the file of this patent UNITED STATES PATENTS 2,585,176 Scherer Feb. 12, 1952 2,593,272 Cohon Apr. 15, 1952 2,644,883 Schoenherr July 7, 1953 2,677,756 Priester May 4, 1954 2,681,321 Stastny June 15, 1954 FOREIGN PATENTS 669,918 Great Britain Apr. 9, 1952 OTHER REFERENCES The Evening Star of Washington, D. C., May 15, 1950. 

1. THE PROCESS OF CONSTRUCTING A LAMP SHADE, COMPRISING: CUTTING A SHET OF SOLIDIFIED-FOAM POLYSTYRENE RESIN INTO GENERALLY RECTANGULAR FORM WITH PARALLEL LONGITUDINALLY EXTENDING EDGE, PASSING SAID SHEET BETWEEN ROLLERS TO OBTAIN A REDUCTION IN THE THICKNESS THEREOF, APPLYING A COATING TO ONE OF THE FACES OF SUCCH REDUCED SHEET, THEN SHAPING SUCH PIECE INTO GENERALLY CYLINDRICAL FORM WITH A SUITABLE SUPPORT FRAME SECURED THERETO AND WITH THE SIDE EDGES IN ABUTTING RELATIONSHIP, AND FINALLY APPLYING A COATING TO THE OTHER FACE OF SUCH PIECE. 